Fluid flow control cock fitted with a lever having several stable positions

ABSTRACT

A valve for controlling the flow of a pressurized fluid, in particular a medical or industrial gas, a fluid inlet, a fluid outlet, and a internal fluid passage that connects them. A valve for controlling the fluid flow can prevent the circulation of a fluid in this passage, and an actuator utilizing a pivoting lever can be manually actuated by an operator. This lever pivots around a pivot point and can move between at least three stable, angularly staggered positions including a rest position where there is zero fluid flow in the internal fluid passage a intermediary released position where the fluid flow remains zero and an active position with fluid flowing thorough the internal fluid passage at a non-zero rate.

BACKGROUND OF THE INVENTION

The present invention relates to a cock for controlling the flow rate ofa fluid, particularly a pressurized gas, and to a gas container, such asa pressurized gas cylinder, equipped with such a cock.

Industrial and medical gases are usually packaged in containers such asgas cylinders in which the gas is kept under a pressure that may be ashigh as 200 to 300 bar, or even more.

When there is a desire to use some pressurized gas, it is necessary toextract it from the container in which it was packaged, and to do this,use is made of a device known as a cock that allows the outlet and flowrate of fluid from the container to be controlled.

There also exist cocks that incorporate a pressure-reducing part so thatthe pressure of the fluid leaving the container can be reduced. Theseare then known as integrated pressure reducing cock assemblies, such anassembly being described in documents EP-A-747796 or EP-A-275242.

Many known cocks for gas cylinders have a common and very simplearchitecture, namely they are made up of a cock body, generally made ofmetal or metal alloy, such as brass, particularly comprising: a threadedbase so that it can be fixed onto the neck of a gas cylinder forexample; a gas outlet coupling via which the gas can be removed to thesite where it is to be used; an internal passage formed in the cockbody, fluidically connecting a gas inlet orifice borne by the base andvia which the gas leaving the cylinder enters the cock body, and a gasoutlet orifice borne by the outlet coupling and via which the gas whichis passed through the cock body reemerges from said cock body and isthen removed, via a gas line, for example, to its place of use; a systemfor controlling the flow rate to control the flow rate of gas in theinternal passage formed in the cock body; and a manipulating means thatcan be actuated by an operator and collaborates with the flow ratecontrol system to allow or prevent, as the operator desires, gas frombeing channeled through the internal passage and therefore from leavingvia the outlet coupling.

The assembly comprising the inlet orifice, the internal passage and theoutlet orifice is sometimes known as the gas distribution circuit.

Most of the time, the cock body also comprises a gas filling couplingwith a fill orifice communicating fluidically, via a filling duct alsoformed in the cock body, with the internal gas passage so that thecylinder can be filled without having to remove the cock.

The assembly comprising the fill orifice and the filling duct connectedto the internal passage is sometimes known as the gas filling circuit.

In most cases, the manipulating means with which existing gas cocks arefitted is or comprises a rotary hand wheel that can be operated by handby the operator by turning it about its longitudinal axis, that is tosay that a screwing-in operation performed by the operator on the handwheel will partially or completely interrupt the flow rate of gas in theinternal passage of the body by shutting off this internal passage viathe flow rate control system, whereas a screwing out operation performedon the hand wheel will allow a partial or total flow rate of gas alongthe internal gas passage.

Such operating hand wheels are described in particular in the followingdocuments: U.S. Pat. No. 4,103,806, EP-A-629812, WO-A-82/01580.

Furthermore, certain cocks or assemblies comprising cocks with inbuiltexpansion valves comprise a manipulating means consisting of a leverpivoting about a pivot axis comprising a manipulating end allowing thelever to be grasped manually by the operator so that it can be pivotedangularly, and an active end, bearing the pivot axis, collaboratingdirectly or indirectly with the system for controlling the flow rate ofthe gas so as to allow or, conversely, prevent, gas from being conveyedalong the internal gas passage between the inlet orifice and the outletorifice borne by the outlet coupling.

Such devices with manipulating levers are described in particular in thefollowing documents: EP-A-747796, EP-A-990825, FR-A-2801689,EP-A-1026438 and GB-A-723828.

The use of a pivoting lever rather than of a rotary hand wheel has theparticular advantage that it is quicker for the user to manipulate.

In addition, the position of the lever immediately reflects the statusof the cock, that is to say the lever in the rest position correspondsto the passage of gas being interrupted, whereas the lever in the activeposition corresponds to the passage of gas. This avoids or minimizes therisk that the operator will make a mistake by increasing the safety ofuse.

The object of the present invention is to improve cocks of thelever-operated type.

Specifically, in existing lever-operated cocks, the lever usually pivotsbetween two angularly offset stable positions, namely:

-   -   a first position known as the “rest position” in which the        conveying of gas through the distribution circuit of the cock        body is completely interrupted; and    -   a second position known as the “active position” or “gas release        position” in which the conveying of gas through the distribution        circuit of the cock body is allowed, that is to say is no longer        interrupted.

The switch from the rest position to the active position is accomplishedby the operator pivoting the lever from its first angular positioncorresponding to the rest position of the lever into the second angularposition corresponding to the active position.

Actuation of the lever gives rise to direct or indirect collaboration ofthe lever via its active end, with the gas flow rate control system inorder to allow gas to pass through the passage opening which washitherto shut off by the gas flow rate control system.

Furthermore, the switch from the active position to the rest position isaccomplished by the operator operating the lever the other way.

This is clearly explained in document EP-A-747796 which discloses apressure reducing cock with a pivoting lever pivoting between twoextreme positions, open or closed, in which positions the lever is heldstably and in a way that is practically insensitive to vibration.

Now, it has been found that, in order to better hold the lever in therest position so as to ensure an effective shutting-off of the gas flow,it was desirable to hold the lever secured to the cock body byappropriate fixing means so as to avoid unwanted opening of the gaspassage by unintentional actuation of the lever.

From there, a proposal was made to give the lever a catching mechanismallowing it to be secured to the cock body, thus guaranteeing a zero gasflow rate in the internal gas passage when the lever is held in its restposition.

However, in practice, it was found that with such a catching mechanism,problems could arise when moving from the rest position to the activeposition.

Specifically, if the catching mechanism holds the lever too firmlysecured to the cock body then the operator may experience difficulty indetaching it when he wishes to pivot it and open the gas supply, andthis may cause the operator to manipulate the lever excessivelyviolently and cause excessively rapid opening of the gas flow, thisbeing accompanied with the usual risks and problems that result fromexcessively sharp handling of pressurized gas. This disadvantage isaccentuated all the more if the lever is attached to and held in therest position very close to the cock body because then the space for theoperator's hands or fingers may not be sufficient, especially if he iswearing working gloves.

Conversely, if the catching mechanism does not hold the leversufficiently, then it will not play its part correctly.

The object of the invention is therefore to propose an improvedlever-operated cock that allows the problem encountered when switchingfrom the rest position to the active position to be solved, particularlywhen the lever is secured to the cock in its rest position by a catchingmechanism.

SUMMARY OF THE INVENTION

The solution of the invention is therefore a cock for controlling theflow rate of a pressurized fluid, particularly a gas, comprising a cockbody comprising:

-   -   an internal fluid-distribution circuit comprising a fluid inlet        orifice, a fluid outlet orifice and an internal fluid passage        fluidically connecting the fluid inlet orifice to the fluid        outlet orifice,    -   fluid flow control means acting on the internal fluid passage to        allow or prevent fluid from flowing along said passage between        the fluid inlet orifice and the fluid outlet orifice,    -   manipulating means that can be actuated manually by an operator        and collaborating directly or indirectly with the fluid flow        control means to allow or to prevent said circulation of fluid        along said passage, and in which the manipulating means comprise        a lever of axis (YY) pivoting about a pivot axis (XX) and able        to move between at least three stable and angularly offset        positions, said three stable positions being at least:    -   a rest position in which the lever is held, directly or        indirectly, fixed and secured to the body of the cock and in        which the fluid flow control means completely shut off the        internal fluid passage so as to obtain a zero fluid flow rate in        said internal fluid passage,    -   a liberating intermediate position in which the axis (YY) of the        lever is offset by a positive and non-zero angle α with respect        to the axis (YY) of the lever in the rest position, in which        position the lever is detached from the body of the cock and in        which position the fluid control means completely shut off the        internal fluid passage so as to provide a zero fluid flow rate        in said internal fluid passage, and    -   an active position in which the axis (YY) of the lever is offset        by a positive and non-zero angle β with respect to the axis (YY)        of the lever in the liberating intermediate position, in which        position the lever is detached from the body of the cock and in        which position the fluid flow control means no longer shut off        the internal fluid passage so as to allow fluid to circulate at        a non-zero flow rate along said internal passage.

A stable position is to be understood as meaning an angular positionwith respect to the axis (XX) in which the axis (YY) of the lever is inequilibrium, that is to say that it holds itself or is held in thisposition in a way that is lasting without perceivably deflecting fromthis position.

The cock of the invention may have one or more of the followingtechnical features as the case may be:

-   -   the fluid flow control means comprise a shut-off means allowing        the internal fluid passage to be shut off, preferably the        shut-off means is a shutter normally pushed back against its        valve seat by an elastic means such as a spring.    -   the pivoting lever comprises a manipulating end via which the        operator can manually grasp the lever, and an active end        situated on the same side as the pivot axis (XX), collaborating        directly or indirectly with the shut-off means for shutting off        the internal fluid passage.    -   the pivoting lever collaborates, via its active end, with the        fluid flow control means (4) by way of at least one moving part        able to move in translation in a housing situated between said        active end of the lever and the shut-off means shutting off the        internal fluid passage.    -   the cock body is covered with an external structure forming        peripheral cladding for said body, said external structure being        secured to the body, and in that, in the rest position, the        lever is held indirectly secured to the body of the cock by        being fixed to the external structure by way of catching means.    -   in the rest position, the lever is secured to the body of the        cock by way of catching means while at the same time being kept        fixed to said body or to an external structure forming        peripheral cladding of said body or a connecting piece borne by        said body.    -   in the liberating intermediate position, the axis (YY) of the        lever is angularly offset by an angle of between 10° and 70° to        the axis (YY) of said lever in the rest position, preferably by        an angle α of between 20° and 50°.    -   in the active position, the axis (YY) of the lever is offset by        an angle β of between 20° and 150° to the axis (YY) of said        lever in the liberating intermediate position, preferably by an        angle β of between 30° and 120°.    -   when the lever is pivoted from the liberating intermediate        position into the active position, the active end of the lever,        situated on the same side as the pivot axis (XX), comprising a        cam-forming portion, collaborates with the shut-off means for        shutting off the internal fluid passage by way of the moving        part able to move in translation in the housing by exerting, via        the cam-forming part, a pressure force on the moving part so as        to cause said moving part to move in translation in the        direction that tends to move said moving part away from said        cam-forming part so as to allow a flow rate of fluid to        circulate in the internal fluid-distribution circuit.    -   the fluid inlet orifice is borne by a base of the body        comprising a peripheral external screw thread and the fluid        outlet orifice is borne by a fluid outlet coupling.    -   it further comprises a pressure gauge connected to the internal        fluid distribution circuit by a pressure tapping formed in the        body in such a way as to cause said pressure gauge said internal        fluid-distribution circuit to communicate fluidically.    -   it further comprises a filling coupling comprising a fill        orifice in fluidic communication with the internal        fluid-distribution circuit by way of an internal        fluid-distribution circuit filling circuit.    -   it further comprises a rigid external structure forming        peripheral cladding for at least part of the cock, said        structure being borne by and secured to said body, preferably        the rigid external structure forming peripheral cladding is        formed of a shaped and cured polymer material.    -   in the rest position, the lever is kept secured to the rigid        external structure forming peripheral cladding by way of        catching means comprising a spherical head borne by the lever        and a complementary receptacle borne by the external structure        sized and shaped to accommodate and hold securely within it the        spherically-headed stud borne by the lever.

The invention also relates to a pressurized-fluid container equippedwith a cock according to the invention, preferably the container is agas cylinder.

The cock of the invention is particularly well suited to use in thefield of welding to contain gas at pressures in excess of 100 bar,typically between 150 and 350 bar, but may also be used in the fields ofspecial gases (laboratory, calibration, etc), in the medical, electronicand foodstuffs fields, etc.

The cock of the invention has numerous advantages, particularly improvedease and comfort of use and speed of opening and of closing withoutrisk, and therefore in complete safety.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects for the presentinvention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like elements are given the same or analogous reference numbersand wherein:

FIG. 1 illustrates a three-dimensional view of an apparatus inaccordance with one illustrative embodiment of the present invention.

FIG. 2 illustrates a view from above an apparatus in accordance with oneillustrative embodiment of the present invention.

FIG. 3 illustrates a side view of an apparatus in accordance with oneillustrative embodiment of the present invention.

FIG. 4 illustrates a view in section on B-B depicted in FIG. 2 inaccordance with one illustrative embodiment of the present invention.

FIG. 5 illustrates a view in section A-A of FIG. 2 in accordance withone illustrative embodiment of the present invention.

FIG. 6 illustrates a view in section C-C of FIG. 2 in accordance withone illustrative embodiment of the present invention.

FIG. 7 illustrate a side view of an apparatus in rest position inaccordance with one illustrative embodiment of the present invention.

FIG. 8 illustrates a side view of an apparatus in rest position, in theliberating intermediate position, and in the active position inaccordance with one illustrative embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

One embodiment of the cock of the invention will now be described ingreater detail with reference to the attached figures.

FIG. 1 depicts a three-dimensional view of one embodiment of a cockaccording to the invention, where there can be seen the body 1 of thecock, generally made of metal or metal alloy, such as brass, with a base17 intended to be fixed by way of a peripheral external screw thread 18onto a gas cylinder, for example, the base 17 bearing a fluid inletorifice 31 allowing pressurized gas to enter the body 1, which conveysit, via an internal gas-distribution circuit 3, 31, 32, as far as theoutlet orifice 32 borne by the outlet coupling 19, to which a userconnector may be coupled.

The body 1 also comprises a pressure gauge 40 connected to the internalfluid distribution circuit 3, 31, 32 by a pressure tapping 41 formed inthe body 1 so as to cause said pressure gauge 40 and the internalpassage 3 of the internal fluid-distribution circuit to communicatefluidically and thus allow the pressure of the gas flowing through thecock body 1 to be measured and indicated as detailed in FIG. 6.

The body 1 further comprises a filling coupling 50 comprising a fillorifice 51 in fluidic communication with the internal distributioncircuit 3, 31, 32 by way of a filling circuit and allowing the cylinder,when empty, to be filled with pressurized gas and for this to be donewithout there being a compulsory need to remove the cock from thecontainer on which it is mounted.

FIG. 2 is a view from above of the cock of FIG. 1 and FIG. 3 is a sideview of the cock of FIG. 1.

FIG. 4 is a view in section on B-B depicted in FIG. 2 showing in detailthe fact that the body 1 comprises an internal fluid-distributioncircuit 3, 31, 32 comprising a fluid inlet orifice 31 borne by the base17, a fluid outlet orifice 32 borne by the outlet coupling 19 and aninternal fluid passage 3 fluidically connecting the inlet orifice 31 tothe outlet orifice 32 serving to convey the gas inside the body 1.

Fluid flow control means 4 act on the internal fluid passage 3 to allow,or, conversely, prevent, any circulation of gas along the passage. Theseflow control means 4 conventionally comprise a shut-off means, such as amoving shutter normally pushed back against a valve seat formed on theinternal gas passage 3 by an elastic means, such as a spring.

According to the invention, the body 1 of the cock of the manipulatingmeans comprising a lever 2 that can be operated manually by an operator,collaborate directly or indirectly with the fluid flow control means toallow or prevent the circulation of fluid along said passage by actingdirectly or indirectly on said shutoff means 4.

More specifically, the manipulating means comprise a lever 2 ofprincipal axis YY, pivoting about a pivot axis XX, which lever is ableto move and be moved between at least three stable and angularly offsetpositions (PS1 to PS3) as shown in FIG. 8, namely:

-   -   a first stable position (PS1) known as the rest position, in        which the lever 2 is held, directly or indirectly, fixed and        secured to the body 1 of the cock and in which the flow control        means 4 completely shut off the internal passage 3 so as say in        this rest position the lever 2 is immobilized in the rest        position and the gas does not flow along the internal gas        circuit.    -   a second stable position (PS2) known as the liberating        intermediate position, in which the axis YY of the lever 2 is        offset by a positive and non-zero angle α, for example an angle        α of the order of 30 to 45°, to the axis YY of the lever 2 when        the latter is in its rest position, the vertex of the angle α        being the point P of intersection of the axis XX with the axis        YY as shown in FIG. 2. In this position, the lever 2 is detached        from the body 1 of the cock, that is to say freed from said        body, but the fluid flow control means 4 continue to perform        their part by completely shutting off the internal passage 3. In        other words, even though the lever 2 has been moved angularly in        a circular arc of angle α, in this second stable position the        lever 2 still does not act on the flow control means 4 and these        therefore continue to prevent any circulation of fluid along the        passage 3 toward the outlet orifice 32, that is to say that the        shutter 4 is still pushed back against its seat, thus shutting        off the passage 3.    -   a third stable position (PS3) known as the active position, in        which the axis YY of the lever 2 is offset by a positive and        non-zero angle β, for example by an angle of 20° to 100° from        the axis YY of the lever 2 in its liberating intermediate        position. In the active position, the lever 2 is detached from        the body 1 of the cock and the fluid flow control means 4 no        longer shut off the internal fluid passage 3, and this allows        gas to circulate at a non-zero flow rate along said internal        passage 3.

The axis XX is defined as being the axis of pivoting of the lever 2 onthe body 1 of the cock, as illustrated in FIG. 2.

Furthermore, the position of the lever 2 at rest serves as a referencefor defining the starting axis YY and the angles α and β. For greatersimplicity, the axis YY will be chosen as shown in FIG. 2, the axes;however, in order to define the axis of the lever 2, it would also bepossible to choose some other straight line passing through the point Pand perpendicular to the pivot axis XX because the most important thingis always to use the same frame of reference in terms of axes.

FIG. 5 is a diagram in section on A-A of FIG. 2, showing thearchitecture of the gas outlet coupling 19 bearing the outlet orifice32. This figure also shows a shutter 45 that can move in terms oftranslation.

Furthermore, FIG. 6 is a diagram in section on C-C of FIG. 2, providingan understanding of how the lever 2 collaborates with the flow controlmeans, particularly the shutter 4, by way of the moving part 5 able tomove in its housing 15, which is normally pushed back in the directionof the active end 12 of the lever 2 under the influence of an elasticpushing force which is imparted to it by a sprung means 13 arranged inthe housing 15.

More specifically, when the operates manipulates the lever 2 to move itfrom the first angular position known as the rest position to the secondangular position known as the intermediate liberating position, theactive end 12 of the lever 2 does not exert pressure (or alternativelyexerts very light pressure) on the moving part 5 which therefore remainsin position and the shutter 4 remains firmly against its seat 24 underthe influence of the pushing force imparted by the spring 14, thuskeeping the gas passage 3 shut off.

By contrast, when the operator manipulates the lever 2 to move it fromthe second angular position known as the intermediate liberatingposition into the third position known as the active position, theactive end 12 of the lever 2 which pivots about the axis XX acts, in themanner of a cam, on the upstream end 5″ of the moving part 5, exertingthereon a pressure force stronger than the opposite force of the spring13, thus causing the moving part 5 to move in translation in its housing15, compressing the spring 13. This movement of the moving part 5 thencauses the shutter 4 to move off its seat 24 under the influence of thepressure force imparted to said shutter by the downstream end 5′ of themoving part 5, this pressure force being stronger than the opposingforce of the spring 14. The lifting of the shutter 4 off its seat willthen liberate the passage 3 and thus allow the gas to flow toward theoutlet orifice 32 of the coupling 19.

As a preference, the cock body 1 is covered with an external structure25 forming partial or complete peripheral cladding of said body 1 andsecured to said body 1, being fixed thereto. The rigid externalstructure 25 is formed for example of several subparts made of a shapedand cured polymer, for example two rigid plastic half shells assembledtogether to clad the body 1 of the cock in order to give it a shape thatis pleasant to look at (design).

As shown schematically in FIG. 7, in the rest position, the lever 2 iskept indirectly secured to the body 1 of the cock by being fixed to saidexternal structure 25 (sectioned view in FIG. 7) by way of catchingmeans 8, 9 comprising a stud with a spherical head 8 borne by the lever2 and a complementary stud receptacle 9, such as a housing, borne by theexternal structure 25 and sized and shaped to accommodate and holdsecurely within it said spherically-headed stud 8 borne by the lever 2.

In the rest position, the spherically-headed stud 8 of the lever 2 fitsfirmly into the complementary stud receptacle 9 so as to hold the leverfirmly in its rest position and thus prevent any unwanted or accidentalopening of the flow rate.

Conversely, in the intermediate position and in the active position, thestud 8 is disengaged from the complementary receptacle 9, and thisallows the lever to pivot.

The cock of the invention can be used on gas cylinders but may also beused on other pressurized gas containers or receptacles, and to equip afluid pipeline or network of pipelines.

It will be understood that many additional changes in the details,materials, steps and arrangement of parts, which have been hereindescribed in order to explain the nature of the invention, may be madeby those skilled in the art within the principle and scope of theinvention as expressed in the appended claims. Thus, the presentinvention is not intended to be limited to the specific embodiments inthe examples given above.

1. An apparatus for controlling the flow rate of a pressurized fluid,comprising: a) a body, said body comprising an internalfluid-distribution circuit, a fluid flow control means, and amanipulating means; b) said internal fluid-distribution circuitcomprising a fluid inlet orifice, a fluid outlet orifice and an internalfluid passage fluidically connecting said fluid inlet orifice to saidfluid outlet orifice; c) said fluid flow control means acting on saidinternal fluid passage to permit or prevent fluid from flowing alongsaid passage between said fluid inlet orifice and said fluid outletorifice; d) said manipulating means being actuated manually by anoperator and collaborating directly or indirectly with said fluid flowcontrol means to permit or to prevent said flowing of fluid along saidpassage, said manipulating means comprising a lever with a first axispivoting about a pivot axis and able to move between at least threestable and angularly offset positions, said positions comprising a restposition, a liberating intermediate position, and an active position,said lever comprising a first axis and a pivot axis, said levercomprising a manipulating end and an active end; e) said rest positionin which said lever is held, directly or indirectly, fixed and securedto said body and in which said fluid flow control means completely shutoff said internal fluid passage so as to obtain a zero fluid flow ratein said internal fluid passage; f) said liberating intermediate positionin which said first axis of said lever is offset by a positive andnon-zero first angle with respect to said pivot axis of said lever insaid rest position, in which position said lever is detached from saidbody and in which position said fluid flow control means completely shutoff said internal fluid passage so as to provide a zero fluid flow ratein said internal fluid passage; and g) said active position in whichsaid first axis of said lever is offset by a positive and non-zerosecond angle with respect to said first axis of said lever in saidliberating intermediate position, in which position said lever isdetached from said body and in which position said fluid flow controlmeans no longer shut off said internal fluid passage so as to allowfluid to circulate at a non-zero flow rate along said internal fluidpassage, wherein said body is covered with a rigid external structureforming peripheral cladding for said body, said rigid external structurebeing secured to said body, and in that, in said rest position, saidlever is held indirectly secured to the body by being fixed to saidrigid external structure by way of a catching means.
 2. The apparatus ofclaim 1, wherein said rigid external structure is formed of a shaped andcured polymer material.
 3. The apparatus of claim 1, wherein saidcatching means comprises a stud with a spherical head borne by saidlever and a complementary receptacle borne by said external structuresized and shaped to accommodate and hold securely within it saidspherical head stud borne by said lever.